[PowerPC] 32-bit ELF PIC support

This adds initial support for PPC32 ELF PIC (Position Independent Code; the
-fPIC variety), thus rectifying a long-standing deficiency in the PowerPC
backend.

Patch by Justin Hibbits!

llvm-svn: 213427

1 files changed, 10 insertions, 4 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
index f8e84a5..6680413 100644
--- a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
+++ b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "PPC.h"
+#include "PPCSubtarget.h"
 #include "MCTargetDesc/PPCMCExpr.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Twine.h"
@@ -39,12 +40,14 @@ static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO, AsmPrinter &AP){
   Mangler *Mang = AP.Mang;
   const DataLayout *DL = TM.getDataLayout();
   MCContext &Ctx = AP.OutContext;
+  bool isDarwin = TM.getSubtarget<PPCSubtarget>().isDarwin();
 
   SmallString<128> Name;
   StringRef Suffix;
-  if (MO.getTargetFlags() == PPCII::MO_DARWIN_STUB)
-    Suffix = "$stub";
-  else if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG)
+  if (MO.getTargetFlags() == PPCII::MO_PLT_OR_STUB) {
+    if (isDarwin)
+      Suffix = "$stub";
+  } else if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG)
     Suffix = "$non_lazy_ptr";
 
   if (!Suffix.empty())
@@ -68,7 +71,7 @@ static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO, AsmPrinter &AP){
 
   // If the target flags on the operand changes the name of the symbol, do that
   // before we return the symbol.
-  if (MO.getTargetFlags() == PPCII::MO_DARWIN_STUB) {
+  if (MO.getTargetFlags() == PPCII::MO_PLT_OR_STUB && isDarwin) {
     MachineModuleInfoImpl::StubValueTy &StubSym =
       getMachOMMI(AP).getFnStubEntry(Sym);
     if (StubSym.getPointer())
@@ -136,6 +139,9 @@ static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
       break;
   }
 
+  if (MO.getTargetFlags() == PPCII::MO_PLT_OR_STUB && !isDarwin)
+    RefKind = MCSymbolRefExpr::VK_PLT;
+
   const MCExpr *Expr = MCSymbolRefExpr::Create(Symbol, RefKind, Ctx);
 
   if (!MO.isJTI() && MO.getOffset())